Null Pointer Dereference Vulnerability in Linux Kernel's VxLAN Module

CVE-2026-74406

What is CVE-2026-74406?

A vulnerability exists in the VxLAN module of the Linux kernel, where a potential null pointer dereference may occur during the process of preparing to receive packets. This issue arises from the improper handling of the user data associated with socket structures in the vxlan_gro_prepare_receive() function. If udp_tunnel_sock_release() sets the socket's user data to NULL while packet processing is ongoing, it could lead to unexpected behavior or crashes. To mitigate this, the kernel has implemented checks using rcu_dereference_sk_user_data() after initializing the checksum in the skb_gro_remcsum_init() function. System administrators are encouraged to apply the latest patches to ensure protection against this vulnerability.

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